Translating hinge

ABSTRACT

A translating hinge includes a translation element which provides translational movement between two objects coupled by the translating hinge and a rotating assembly coupled to the translation element.

RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.61/162,748 filed on Mar. 24, 2009 under 35 U.S.C. §119(e) whichapplication is hereby incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The structures and techniques described herein relate to bearings andmore particularly to hinges.

BACKGROUND OF THE INVENTION

As is known in the art, a bearing is a device which allows constrainedrelative motion, typically rotation or linear movement, between twoparts or objects. Bearings may be classified broadly according to themotions they allow and according to their principle of operation as wellas by the directions of applied loads they can handle.

A hinge is a type of bearing that connects two objects, typicallyallowing only a limited angle of rotation between the objects. Twoobjects connected by an ideal hinge rotate relative to each other abouta fixed axis of rotation (the geometrical axis of the hinge). Hinges maybe made of rigid or flexible material and/or of moving components.Hinges are employed in many types of doors, movable bridges, furniture,electronics, automobile doors or in any structure which it is desirableto have two objects connected but which can rotate relative to eachother.

A translating hinge is a particular type of hinge which allows both atranslating motion and a rotation. Two techniques have conventionallybeen used to provide translating hinges. One technique utilizes four barlinkages and another technique utilizes slotted hinge assemblies. Someof the drawbacks of the four bar linkage techniques are: (1) theresulting hinge does not translate in a direction which is perpendicularto a mating surface; (2) the resulting hinge has many moving parts; (3)the resulting hinge is a relatively bulky assembly and thus limits thelocations/applications in which the hinge can be used. Some of thedrawbacks of the slotted hinge techniques are: (1) rotation can occurbefore translation is complete (which could be undesirable in someapplications which require translation to be complete prior torotation); (2) the resulting hinge is relatively difficult to springload at the translated position; and (3) tight tolerances are relativelydifficult to achieve due to the precision with which a slot can beprovided in the hinge structure since in general, fabrication of slotsis typically accomplished by interpolating an outer profile of the slotwith an end mill of a smaller diameter than the slot width. Slotsprovided using this technique struggle to achieve tolerances greaterthan +/−0.002 in. especially when the ratio of slot depth to end milldiameter exceeds 5 to 1.

SUMMARY OF THE INVENTION

In accordance with the techniques and concepts described herein, atranslating hinge includes a translation element which providestranslational movement between two objects coupled by the translatinghinge and a rotating assembly coupled to the translation element.

With this particular arrangement, a translating hinge configured forboth translational and rotational movement is provided. When thetranslating hinge couples two objects having surfaces in contact or inproximity to each other, the translation element allows the objects totranslate in a direction which is perpendicular to the surfaces of theobjects (sometime referred to herein as true vertical translation). Inone embodiment, the translation element includes a shaft which guidesthe movement of an object being translated. In some embodiments, thetranslation element includes a spring which provides a force to move theobject. In other embodiments, the translating hinge and objects may bearranged such that the force to move the object may be provided bygravity, for example. Alternatively still, an external force-providingdevice (e.g. a pneumatic or other device) may be used to provide a forceto cause movement of the object. Such force-providing devices may beprovided as an integral part of the translating hinge (e.g. mechanicallycoupled to the translation element) or may be separate from thetranslating hinge. In cases in which a spring is used, by selecting thesize and stiffness of the spring to be self-supporting, the spring cansupport the weight of the object being rotated. Stated differently, thetranslating hinge can hold an object being rotated in a plurality ofdifferent positions during a rotation movement. In one embodiment, thespring is provided as a coil spring and the shaft in the translationelement is provided as a screw. In one embodiment, the screw is providedas a shoulder screw disposed through a counter-bored threaded hole inthe rotating assembly and through a central region of the coil spring.

In the coil spring embodiment, outside/inside diameters of the springare selected such that the spring fits over a shank of the shoulderscrew but are not so large that the spring would take up too much space.Also the force (stiffness)/compression characteristics of the spring areselected such that the force provided from the spring exceeds the weightof the object the hinge is supporting when the hinge is in thetranslated position. The spring force increases proportionally to thecompression. Thus, the spring must provide enough force in thetranslating position to hold the object being moved while still havingenough range of motion to compress without bottoming out in a stowedposition of the translating hinge.

Spring stiffness is derived from the material from which the spring ismade, and the geometry of the spring (e.g. coil diameter, wire diameter,# coil turns per inch). In preferred embodiments, the spring is not usedbeyond a load length (i.e. a length slightly larger than the solidheight which is a maximum compressed length of a spring). Not using thespring beyond its load length avoids reaching the solid height. It isdesirable to avoid compressing the spring to its solid height becausethen the applied load would spike by a considerable amount, as thesystem would be compressing solid metal as opposed to bending themetal). Another important factor to consider is the free length of thespring (i.e. the length of the spring when no force is applied). Itshould be noted that there may exist different springs with the samestiffness constant that have different free and load lengths, dependingupon the geometry and material characteristics (from which is derivedthe stiffness constant). It should of course, be appreciated that thespring may be provided as a compression spring, an extension spring oranother type of spring could be used.

If the translating element and rotating element are provided fromtightly toleranced parts (e.g. provided by a machining operation whichachieves specified part dimensions with small variations) and by using acounter-bored threaded hole for the shoulder screw, the translatinghinge can provide very precise alignment between the hinged objects. Thepurpose of the counter bore is for alignment of the shoulder screw. Suchprecise alignment is desirable, for example, in applications whichrequire mating of mechanical and/or electrical interconnects (includingbut not limited to blind mate interconnects) disposed on separateobjects coupled by the translating hinge. Furthermore, this approach(i.e. utilizing tightly toleranced parts) eliminates the need for anyother alignment features between the objects being coupled by thetranslating hinge. The translating hinge described herein is thusappropriate for use in applications requiring critical alignment betweenhinged objects. For example, in applications which require mating ofelectrical connections between two objects, mating of mechanicalconnections between two objects and/or in applications in whichEMI/weather gaskets are disposed between two objects and/or inapplications in which two objects have mechanical features which must bealigned.

Also, by including in the hinge a spring which can support and hold anobject during a rotation operation and which can firmly hold an objectin a rotated position, the translating hinge helps prevent the supportedobject from accidental contact and potential damage with proximatelylocated objects or other structures within a predetermined envelope ofrotation. Thus, by properly sizing the spring such that the springprovides enough force to firmly hold an object in one or more rotatedpositions during a rotation operation, the hinge is said to be selfsupporting during rotation. In an environment in which objects arearranged in close proximity to each other (i.e. in a tightly packedenvironment), the self supporting feature helps prevent accidentalcontact and potential damage between neighboring structures.

Furthermore, the rotating assembly of the translating hinge describedherein allows access to objects within tightly packed structures. Byrotating one object in a given direction, access to other objectslocated below the rotated object is provided. In a radar system havingtightly packed components, for example, the translating hinge allowsaccess to components within the radar system without removing othercomponents from the radar system and without disturbing neighboringcomponents to gain accessibility to a desired component.

Since the translation element provides true vertical translation, thetranslating hinge allows for the effective use of EMI/weather gasketsand electrical interconnects between the hinged objects. In oneembodiment described herein in which the translation element comprises ashoulder screw, the translation length can be modified by shortening orlengthening the shoulder screw. The ability to easily lengthen orshorten translation length increases the design flexibility for hingingobjects of different thicknesses and/or heights and/or other mechanicalcharacteristics. Thus, the translating hinge can be provided as a highprecision, self supporting hinge with an internal axis of rotation andtrue translational component.

Additionally, the translating hinge described herein allows access tohinged objects having interfacing surfaces thereby facilitatingdisassembly and rework when needed.

In one application, for example, translating hinges of the typedescribed herein can be used in electronic systems such as radarsystems. Such translating hinges are particularly useful in radarsystems having array antennas fabricated in accordance with a so-called“panel architecture” such as that described in U.S. Pat. No. 7,348,932assigned to the assignee of the present invention. Array antennas havinga panel architecture such as that described in the aforementioned U.S.Pat. No. 7,348,932 can utilize layering or stacking of electronics asthis allows the array antenna to be relatively thin (and thus the arrayantenna is said to have or maintain a low profile).

The electronics, however, contain components which utilize electricalpower (typically from a DC signal) and the components dissipate energyin the form of heat. Stacking the electronics to form a panel can thusresult in the antenna panel generating a substantial amount of thermalenergy. Consequently, the antenna panel (and in particular theelectronics within the antenna panel) need to be cooled. Radar systemswhich operate in the medium to high power range often rely on heat sinkswhich use liquid cooling often referred to as cold plates. Thus, theantenna panel is coupled to a cold plate (or a portion of a cold plate).Similarly, electronics used in the radar system and proximately locatedto the antenna panels also dissipate energy in the form of heat and thusare also coupled to a second cold plate. To maintain a low profile, theelectronics are disposed in a recess region of the second cold plate. Ifthe two cold plates are coupled together (e.g. by screws or the like),the electronics are effectively inside a cavity region and thus are notaccessible without separating the two cold plates.

By coupling the two cold plates via a translating hinge the cold platescan be separated thereby providing access to the electronics. Thus,coupling the cold plates via a translating hinge is beneficial becausethe translating hinge captivates both assemblies (i.e. both cold plateswith the associated electronics) thus improving serviceability of bothassemblies.

Furthermore, since the two heat sinks are coupled via the translatinghinge, it is not necessary to completely separate the two heat sinks forservicing either the heat sinks or the electronics. Since neither heatsink is loose during service, this reduces the chance of damage toeither assembly while one (or both) of the assemblies is being serviced.Coupling the heat sinks via translating hinges can also eliminate theneed for a coolant quick disconnects that would otherwise be required toseparate the cold plates. Fewer quick disconnect couplings means fewerleaks and a more robust, reliable system. Furthermore, the translatinghinge described herein allows electrical interconnections between thetwo assemblies to remain intact during servicing. This reduces thepossibility of damage to connectors (e.g. due to disconnecting andreconnecting electrical connectors) and allows access to the heat sinksand electronics and testing thereof to be performed in an easilyaccessible configuration.

By allowing for more than two layers of components to be hinged togetherand independently accessible, the translating hinge described hereinalso provides a framework for future growth of RF systems utilizingpanel array antenna architectures. For example, a stack of three or morecold plates could be coupled via translating hinges. Assemblies otherthan cold plates or heat sink assemblies could also be stacked. Forexample, multiple electronics modules which do not require a heat sinkcould be stacked. Or combinations of cold plates, heat sinks and/orelectronics modules could be coupled via translating hinges. Thus, thehinge itself is scalable to operate with objects of different sizes andshapes while at the same time providing system scalability.

The translating hinge described herein thus preferably incorporates atleast one or more of the following characteristics: (1) the hinge axisof rotation is within a predefined envelope of an LRU which allowsserviceability of the LRU while assembled into a tightly packedstructure (e.g. a RF system having a panel architecture); (2) having theaxis of rotation within the LRU envelope requires translation beforerotation; (3) the object undergoing the translation movement is stablein a translated position; (4) the two objects coupled by the translatinghinge can be precisely aligned to each other to allow accurate blindmating to occur (e.g. blind mating of electrical interconnects and/orEMI gaskets between the two objects).

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing features of this invention, as well as the inventionitself, may be more fully understood from the following description ofthe drawings in which:

FIGS. 1-3 are a series of isometric views showing front, back and sideviews of a radio frequency (RF) transmit/receive system;

FIG. 3A is a cross-sectional view of a(line replaceable unit (LRU) shownin FIG. 3 and taken across lines 3A-3A in FIG. 3;

FIG. 3B is a cross-sectional view of a plurality of LRUs;

FIG. 4 an enlarged top view of a hinge on the radio frequency (RF)transmit/receive system—taken across lines 4-4 in FIG. 2;

FIGS. 5-5C are a series of end views of a line-replaceable unit (LRU)which illustrate a process of releasing a translating hinge and rotatingan object which comprises the LRU;

FIG. 6 is an enlarged isometric view of a translating hinge in anengaged position;

FIG. 6A is an enlarged isometric view of the translating hinge of FIG. 6in a translated position;

FIG. 7 is an isometric view of a translating hinge;

FIG. 7A is an exploded isometric view of the translating hinge of FIG.7;

FIGS. 8-8F are a series of views which illustrate translating hingescoupling a plurality of objects and the process of releasing thetranslating hinges.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Described herein is a translating hinge which can be used to couple twoobjects. Before describing a translating hinge, it should be appreciatedthat reference is sometimes made herein to a translating hinge beingused in a radio frequency (RF) transmit/receive system and in particularin a radar system having a so-called panel architecture. It should alsobe appreciated, however, that references to such radar systems are madeonly for the purpose of promoting clarity in the description anddrawings with respect to the concepts being described and claimed andsuch references are not intended to be, and should not be, construed aslimiting.

It is fully appreciated that the translating hinge concepts describedherein find use in a wide variety of applications including bothcommercial and military applications. The translating hinge conceptsdescribed herein may find particular use in any application in which itis desired to include a hinge which provides both a translation motionand a rotation motion. The translating hinge concepts find particularuse in applications in which structures are closely spaced and access tocertain portions of a structure is needed. Such applications include butare not limited to doors, movable bridges, furniture, electronics,appliances (waffle makers, etc.), copy machines, automobiles, RF systemsincluding RF radar systems having a panel architecture or in anystructure which includes two objects which would benefit from beingrotatably coupled.

Referring now to FIGS. 1-4, in which like elements are provided havinglike reference designations throughout the several views, a portion of aradar, communications or other radio frequency (RF) transmit/receivesystem includes an array antenna 10 provided from a plurality (or array)of so-called RF “antenna panels” 12 a-12N, generally denoted 12(sometimes more simply referred to herein as “panel 12”). Thus, arrayantenna 10 is said to have a “panel architecture.” One example of anantenna panel is described in U.S. Pat. No. 7,384,932 assigned to theassignee of the present invention.

In preferred embodiments, the antenna panels 12 are stand alone units.That is, the panels 12 are each independently functional units (i.e. thefunctionality of one panel does not depend on any other panel). Forexample, the feed circuit for each panel 12 are wholly contained withinthe panel itself and is not coupled directly to any other panel. Thus,in the event that one panel 12 fails, the panel 12 may simply be removedfrom the array 10 and another panel can be inserted in its place. Thischaracteristic is particularly advantageous in RF transmit/receivesystems deployed in sites or locations where it is difficult to servicethe RF system in the event of some failure.

As described in the aforementioned U.S. Pat. No. 7,389,432, it ispreferable for the antenna panels used in antennas having a panelarchitecture to maintain a low profile. This can be accomplished byutilizing a plurality of multilayer circuit boards which provide one ormore circuit assemblies in which RF and other electronic components aredisposed in close proximity with each other. The operation of suchelectronic components utilizes electrical power and thus the componentsdissipate energy in the form of heat. Thus, the antenna panels 12 mustbe cooled.

As shown in FIGS. 1-3B, array antenna 10 (and more specifically RFpanels 12) are coupled to a panel heat sink 14. In this exemplaryembodiment, heat sink 14 is comprised of a plurality, here four,separate sections 14 a-14 d. A first surface of each heat sink section14 a-14 d is designated 15 a and a second opposing surface of each heatsink section 14 a-14 d is designated 15 b. Thus, RF panels 12 arecoupled to the first surface 15 a of heat sink 14.

A rear heat sink 16 is coupled to surface 15 b of heat sink 14. In thisexemplary embodiment, rear heat sink 16 is comprised of a plurality,here four, separate sections 16 a-16 d (FIG. 2). A first surface of eachheat sink section 16 a-16 d is designated 17 a and a second opposingsurface of each heat sink section 16 a-16 d is designated 17 b. Thus,portions of heat sink surface 15 b contact portions of heat sink surface17 a.

A set or combination of heat sink sections and associated panels can beremoved from the array and replaced with another set of heat sinksections and associated panels. Such a combination is referred to as aline replaceable unit (LRU). For example, heat sink sections 14 a, 16 aand the panels dispose on heat sink section 14 a form a LRU 20 a. Thus,the exemplary system of FIG. 1 comprises four LRUs 20 a-20 d with eachof the LRUs comprised of eight panels 12, one of panel heat sinksections 14 a-14 d and a corresponding one of rear heat sink sections 16a-16 d. As will become apparent from the description of FIG. 3Ahereinbelow, in one embodiment, panel heat sink sections 14 a-14 d andrear heat sink sections 16 a-16 d are provided having a “U” shaped crosssectional shape. Thus, when the panel heat sink sections 14 a-14 d andcorresponding rear heat sink sections 16 a-16 d are coupled an internalcavity is formed therebetween in which power and logiccircuits/electronics are disposed.

Referring briefly to FIG. 3A, taking LRU 20 d as representative of LRUs20 a-20 c, each of heat sinks 14 d, 16 d are provided having respectiverecess regions 22, 24 in which electronics 26, 28 are disposed. Thus,when the heats sinks 14, 16 are coupled together, the electronics 26, 28are effectively disposed in a cavity region 25 formed by the recesses22, 24 and associated internal surfaces of the respective heat sinks 14,16. Thus, panel heat sink 14 primarily cools antenna panels 12 andelectronics 26 while rear heat sink 16 primarily cools the electronics28.

It should, of course, be appreciated that in other embodiments otherheat sink configurations may be desired or required. For example, only 1of the heat sinks 14, 16 may be provided having a recess region withelectronics disposed therein. Alternatively, in some embodiments,neither of the heat sinks 14, 16 may be provided having a recess region.The particular manner in which to provide the heat sinks and in which tocouple the electronics depends upon the particular application and thefactors associated with the application.

Referring again to FIGS. 1-3, in one embodiment, heat sinks 14, 16 areprovided as so-called cold plates which utilize fluid to cool any heatgenerating structures (such as panels 12 and electronics 26, 28) coupledthereto. A fluid is fed through channels (not shown) provided in theheat sinks 14, 16 via fluid fittings 29 and fluid paths 18. It should beappreciated that each of the heat sinks 14, 16 may be comprised of aplurality of different components or subassemblies coupled together (asshown in FIGS. 1-3) or alternatively heat sinks 14, 16 may be providedas monolithic structures. In other embodiments, air cooling can be used.

Since the electronics are disposed between a surface of the panel heatsink and an internal surface of the rear heat sink, the electronics 26,28 are not accessible when the panel heat sink 14 and rear heat sink 16are coupled as shown in FIGS. 1-3. Thus, to provide access to the recessregion of the rear heat sink 16 (and thereby provide access to theelectronics disposed in the recess region of rear heat sink 16), one ormore translating hinges 30 couples panel heat sinks 14 a-14 d torespective ones of rear heat sinks 16 a-16 d. Thus, as will becomefurther apparent from the description hereinbelow, the translating hingeallows access to the electronics disposed in recess regions 22, 24thereby facilitating disassembly and rework of the electronics 26, 28(or portions thereof) and/or heat sinks (or portions thereof) whenneeded.

As may be more clearly seen with reference to FIGS. 2, 3 and 4, heatsinks 14 a-14 d are coupled to heat sinks 16 a-16 d via a plurality offasteners 36 and a plurality of translating hinges 30. In the exemplaryembodiment of FIGS. 1-4, fasteners 36 are provided as screws which arecaptive in heat sink 16 and which mate with threaded holes provided inheat sink 14. It should be appreciated that one of ordinary skill in theart will understand how to select an appropriate type and number offasteners 36 to use in any particular application. In one embodiment,fasteners 36 may be provided as spring-loaded, captive screws.

As may be most clearly seen in FIGS. 3 and 4, translating hinge 30couples panel heat sink 14 d to rear heat sink 16 d. Hinging these twoassemblies (i.e. panel heat sink 14 d and rear heat sink 16 d) isbeneficial since when servicing either of the assemblies, hinges 30captivate the heat sinks 14 d, 16 d and thus neither heat sink 14 d, 16d is loose. This reduces the chance of damage to either of heat sinks 14d, 16 d. Also, since neither heat sink is ever loose, the translatinghinges 30 improve serviceability of the heat sinks 14, 16 as well as theserviceability of the electronics 26, 28 disposed in the recess regionsof heat sinks 14 d, 16 d.

It should be appreciated that in FIGS. 2 and 3 each of panel heat sinks14 a-14 d are coupled to respective rear heat sinks 16 a-16 d by a pairof translating hinges, in other embodiments fewer or more than twotranslating hinges may be used. After reading the disclosure herein, oneof ordinary skill in the art will understand how to select anappropriate number of translating hinges to use in any particularapplication.

The translating hinge approach also eliminates the need for a coolantquick disconnect that would be required to separate the two cold plates.Fewer quick disconnects mean fewer leaks and a more robust, reliablesystem. Furthermore, electrical interconnections to (e.g. from externallocations as through RF and DC/logic connectors 32, 34 in FIG. 4) and/orbetween electronics 26, 28 can remain intact during servicing. Thisreduces the possibility of damage to connectors (e.g. due todisconnecting and reconnecting electrical connectors) and also allowsaccess to and testing of the electronics in an easily accessibleconfiguration (e.g. as will be shown and described below in conjunctionwith FIG. 5C).

Referring now to FIGS. 5-5C in which like elements are provided havinglike reference designations thoughout the several views, a linereplaceable unit (LRU) 50 includes a translating hinge 52 which couplesa first object 54 to a second object 56. One or more fasteners 58secures the first and second objects 54, 56. For clarity in thedescription and the drawings, only one fastener 58 is shown. It should,however, be appreciated that although only one fastener 58 is shown inFIGS. 5-5C, those of ordinary skill in the art will appreciate thatmultiple fasteners may be used to secure together objects 54, 56 and itshould also be understood that one of ordinary skill in the art willunderstand how to select an appropriate number of fasteners to use inany particular application. Similarly, although only one translatinghinge is shown in FIGS. 5-5C, it should be appreciated that multipletranslating hinges may be used to couple together objects 54, 56 and itshould also be understood that one of ordinary skill in the art willunderstand how to select an appropriate number of translating hinges touse in any particular application.

The LRU 50 may be the same as or similar to the LRUs 20-20 d describedabove in conjunction with FIGS. 1-4. Similarly, the first object 54 maycorrespond, for example, to a panel heat sink such as panel heat sink 14described above in conjunction with FIGS. 1-4 and the second object 56may correspond, for example, to a rear heat sink such as rear heat sink16 described above in conjunction with FIGS. 1-4. Also, fasteners 58 maybe the same as or similar to captive screws 36 described above inconjunction with FIGS. 1-4 (e.g. fasteners 58 may be provided as captivescrews or as spring-loaded captive screws). Other types of fastenersmay, of course, also be used.

First and second objects 54, 56 have opposing surfaces 54 a, 56 a inproximity (as shown in the exemplary embodiment of FIG. 5, at least someportions of surfaces 54 a, 56 a are in contact with each other). A thirdobject 60 is coupled to a second surface 54 b of object 54. The thirdobject may or may not be coupled to object 54 via one or moretranslating hinges.

In FIG. 5, translating hinge 52 is shown in a closed or engaged positionmeaning that the two objects 54, 56 are coupled such that surfaces 54 a,56 a are in a desired proximity to each other or even in contact witheach other (as shown in FIG. 5).

In FIG. 5A, fastener 58 has been disengaged allowing translating hinge52 to move to its translated position. By moving to its translatedposition, translating hinge 52 raises object 56 with respect to theobject 54. It should be appreciated that translating hinge 52 translatesin a direction which is perpendicular to mating surfaces 54 a, 56 a.Thus, the translating hinge translation element provides the translatinghinge having true vertical translation. This allows for the effectiveuse of EMI/weather gaskets and electrical interconnects, for example,between the objects 54, 56.

It should also be appreciated that in an alternate configuration, thetranslating hinge can be made to rotate parallel to the mating surfaces.It should, however, be appreciated that either all of the axis ofrotation or all of the axis of translation should be aligned to preventbinding of the translating hinges with each other during theirtranslating/rotating operations.

In FIG. 5A, the translation length is indicated by a distance D. One ormore springs 62 (FIG. 5B with only one spring visible in FIGS. 5-5C)provides a force which is large enough to translate and hold object 56above object 54. It should be appreciated, and as will become apparentfrom the description of FIGS. 6-7A, the translation length can bemodified (e.g. either shortened or lengthened) by shortening orlengthening the translation element. In one embodiment, the translationelement also comprises a shoulder screw 64 (FIG. 5B) disposed through acentral longitudinal region of spring 62 and the translation length ismodified (e.g. either shortened or lengthened) by shortening orlengthening the length of the shoulder screw. Suitable adjustments inthe properties of spring 62 may also be required.

As shown in FIG. 5B, once the translating hinge 52 translates andthereby separates object 54 from object 56, object 56 can then berotated vertically away from object 54. In FIG. 5B, object 56 is shownmoved into a ninety degree position with respect to heat sink 14.

It should be appreciated that by properly sizing the spring 62 to firmlyhold the rotating assembly 56 in a retracted position during rotation,the hinge 52 is said to be self supporting during rotation meaning thattranslating hinge 52 can hold object 56 in a desired position. Thisprevents accidental contact and potential damage between coupled objects54, 56 and between other components in proximity to the objects 54, 56such as an adjacent LRU 50 a (FIG. 5C).

With object 56 rotated into a vertical position with respect to object54, portions of electronics generally denoted 66 can be seen. It shouldbe appreciated that one or both of objects 54, 56 may be provided havinga recess region sized to accommodate electronics 66.

When the translating hinge 52 is in its closed position (as shown inFIG. 5), electrical connections between electronics 66 and otherelectronics (not visible in FIG. 5) are made and those electricalconnections may be maintained by utilizing electrical signal paths suchas signal path 70 (FIG. 5C). Thus, electrical connections betweenelectronics 66 and other electronics need not be interrupted by rotatingthe object 56 away from object 54.

Referring now to FIG. 5C, the hinge 52 (and thus object 56) is shownrotated into a 180 degree position and thus LRU 50 is able to nest withan adjacent LRU 50 a. Since the LRUs 50, 50 a are the same height, such180 degree rotation is accomplished by the translating hinge 52 firsttranslating vertically. This moves the axis of rotation 57 oftranslating hinge 52 above a plane 53 defined by a top surface 51 a ofLRU 50 a. It should be noted that hinge 52 a is in its closed (orun-translated) position and that in this position hinge point 57 a isbelow plane 53. If hinge 52 a did not translate hinge point 57 a aboveplane 53, then a mechanical interference between the hinged objectswould occur and without some additional relative movement between theobjects, it would not be possible to open LRU 50 a.

Also, since the translating hinge 52 moves in a true vertical direction(i.e. surface 56 a of object 56 moves in direction perpendicular tosurface 54 a of object 54), the axis of rotation 72 of translatinghinges 52 is able to be within the width envelope of the LRU defined byreference lines 55R, 55L in FIG. 5C. Without the translation motion, theaxis of rotation 72 would need to be outside the width of LRU 50 (i.e.to the right of reference line 55R otherwise the two mating surfaces 54a, 56 a will bind). The translational element of the hinge strictlyenables the axis of rotation to be within the width envelope of the LRUand creates a zone of true vertical translation that may be required forconnector insertion, alignment pin engagement, etc. This is required inembodiments in which the spacing S between adjacent LRUs is small. Forexample in one application the LRU-to-LRU spacing S is approximatelyabout 0.020 in.

It should also be noted that each LRU 50, 50 a has angled or chamferedsides 59. However, if the translation provided by hinges 52, 52 a were alarge enough distance, then angled surface 59 would not be needed. Itshould also be appreciated that the location of the hinge points 57, 57a with respect to the LRU edges (i.e. the plane 55R defined by the sideof the LRU) is proportional to the translation height. In FIG. 5C, thedistance of the hinge point 57 from edge 55R is designated D_(HP). Inone embodiment, the spacing S between LRUs is approximately 0.020 in.and the translation height provided by the translating hinges isapproximately 0.200 in above the surface of the LRU (e.g. for hinge 52a, the distance is approximately 0.200 in above plane 53 defined bysurface 51 a). In this case, the distance D_(HP) is approximately 0.450in.

As mentioned herein, in one embodiment reference to the hinge being“within the envelope” refers to the hinge being within the widthenvelope of an LRU (i.e. within the region defined by LRU edges whichdefine reference lines 55R, 55L. By allowing the object 56 to be rotated180 degrees, the hinge 52 allows serviceability to components (e.g.electronics disposed in recess regions of objects 54, 56) withoutremoving the LRU 50 from a closely packed array of similar LRUs or otherobjects having substantially the same thickness as the LRU having thetranslating hinge coupled thereto. Thus, the translating hinge 52 allowsaccess to LRU 50 without disturbing a neighboring LRU e.g. LRU 50 a (orany other structure).

Referring now to FIGS. 6-7A, in which like elements are provided havinglike reference designations throughout the several views, a translatinghinge 80 couples a first object 82 to a second object 84.

In FIG. 6, one or more fasteners 86 (only one fastener being shown inFIG. 6 for clarity) secure the first and second objects 82, 84 in aclosed or engaged position meaning that surfaces of the two objects 82,84 are in close proximity to each other or in contact with each other.The specific positioning of objects coupled by a translating hingedepends upon a variety of factors and the needs of the particularapplication in which the hinge is being used. For example, in the caseof the RF system having a panel architecture described above inconjunction with FIGS. 1-5C, at least some portions of surfaces of therespective heat sinks 14, 16 are in contact for reasons related tomechanical and electrical connections of the panel array.

It should, however, be appreciated that in other applications actualcontact between surfaces of the objects coupled by the translating hingemay not be necessary or even desired. Thus, the particular dimensions ofthe components which comprise the hinge are selected to satisfy theneeds of the particular application in which the hinge is being used.Those of ordinary skill in the art will appreciate, after reading thedescription provided herein, how to select the particular dimensions ofthe components which comprise the hinge for a particular application.

The translating hinge includes a screw 90 which passes through a hingepin 92 having a pair of yoke blocks 94 a, 94 b projecting from opposingends thereof. In one embodiment, screw 90 is provided as shoulder screw.Use of shoulder screws in alignment applications is sometimes preferredsince such screws are typically fabricated to precise tolerances and areintended for such applications. Thus the tolerance on the shoulderdiameter is made to industry standards. Standard tolerance on thediameter is usually +/−0.001″. Higher precision parts having tolerancesof +/−0.0005″ can also be used. A tightly toleranced shoulder screwaccurately locates the hinge assembly with respect to first and secondobjects 82, 84.

The hinge pin 92 has a first or top surface having a recess 93 providedtherein which accepts a head 91 of the shoulder screw 90. A shank 95 ofthe shoulder screw 90 includes a threaded portion 96 (visible in FIG. 7and 7A). Shank 95 passes through the hinge pin 92. Recess 93 may, forexample, be provided by counter-boring the hinge pin. Other techniquesmay also be used to provide recess 93. The hinge pin keeps the assemblylow profile by allowing the head of the shoulder screw to bury itself inthe pin recess after translation is complete. It should be noted thatthe hinge pin need not be circular. It could be block shape, or othershapes, depending upon the application.

A first washer 98 is disposed over the shank of the shoulder screw andis disposed against a second or bottom surface of the hinge pin 92. Aspring 100 (which may be provided, for example, as a compression spring)is disposed over the shank of the screw. The appropriate springstiffness is selected to ensure translation only occurs when desired. Afirst end of the compression spring is disposed against a surface of thefirst washer 98 and a second end of the compression spring disposedagainst a surface of a second washer 102 which is also disposed over theshank 95 of screw 90. Shoulder washers 98, 102 keep the spring 100centered on the screw 90 and create a relatively smooth bearing surfaceagainst the hinge pin.

The shoulder screw's precise diameter accurately locates the hingeassembly while the two separate yokes 94 a, 94 b and alignment slots 104a, 104 b (FIGS. 7 and 7A) account for spaces (which are a result ofmanufacturing tolerances) between the pin and the yoke and allow suchspaces to be removed during assembly. The tolerance stack-up that existsbetween the hinge pin, yokes and alignment pins on the rear heat sink(e.g. a cold plate) must be accounted for in order to prevent a gapbetween the yoke and hinge pin. If there were to be a gap, the hinge pinwould be free to move up and down which would significantly compromisethe assembly tolerance of the front and rear heat sink assemblies. Thiseffect could result in the shorting of interconnects and/or damage tointerconnects. The slots 104 a, 104 b in the two separate yokes 94 a, 94b solve this problem by accommodating all of the tolerances which occurdue to tolerance stack ups which result due to fabrication of practicalcomponents such as the yoke and hinge pin. The slots 104 a, 104 b fitprecisely over pins 105 (FIG. 6A) in the rear heat sink. This pin/slotconfiguration constrains the yoke in a first direction (e.g. ahorizontal or x-direction) while still allowing the yoke to be pressedup flush in a second orthogonal direction (e.g. a y-direction) to thehinge pin. Once tolerances are eliminated, the fastener 106 (FIG. 6A) oneach yoke is tightened (in a preferred embodiment the fasteners aretorqued to a predetermined level). The result is the two hingedassemblies are now precisely aligned to one another.

It should be appreciated that machined parts having tight tolerances andthe counter bored threaded hole for the shoulder screw ensure veryprecise alignment between hinged objects. In applications which haveblind mate interconnects between the two objects, such precise alignmentprovided by the translating hinge is critical to guarantee blind mateinterconnects can be successfully mated. No other alignment features areneeded between the assemblies. In applications which do not require anyblind mate interconnects, the tolerances need not be as tight whichresults in less expensive parts.

The hinge is made self supporting during rotation by properly sizing thespring to firmly hold the rotating assembly in a retracted positionduring rotation. This prevents accidental contact and potential damagebetween coupled objects and between other components in proximity to theobjects coupled by the translating hinge.

The translation length is indicated by a distance D (FIG. 6A). Asmentioned above in the description of FIGS. 5-5C, the translation lengthcan be modified (e.g. either shortened or lengthened). In the embodimentshown in FIGS. 6-7A, and as will be described in more detailhereinbelow, by changing the length of the shoulder screw 90 (e.g.shortening or lengthening the length of the shoulder screw), it ispossible to change the translation length. Allowing changes in thetranslation length increases the number of different mechanicalstructures which may be coupled by the translating hinge.

As may be most clearly seen in FIGS. 7 and 7A, shoulder screw 90 passesthrough the hinge pin 92 and the pair of yoke blocks 94 a, 94 b projectfrom opposing ends of hinge pin 92. The recess 93 is provided in a firstor top surface of the hinge pin. The recess accepts the head 91 of theshoulder screw 90 while shank 95 of the shoulder screw passes throughthe hinge pin. The counter bored hinge pin keeps the assembly lowprofile by allowing the head of the shoulder screw to bury itself in thepin after translation is complete. A first washer is disposed over theshank 95 of the shoulder screw and is disposed against a second orbottom surface of the hinge pin. A compression spring is disposed overshank 95 of the screw. The appropriate spring stiffness is selected toensure translation only occurs when desired. A first end of thecompression spring disposed against a surface of the first washer and asecond end of the compression spring disposed against a surface of thesecond washer. The shoulder washers keep the spring centered on thescrew and created a smoother bearing surface during rotation

Shoulder screw's precise diameter accurately locates the hinge assemblywhile the two separate yokes and alignment slots account for spaces(which are a result of manufacturing tolerances) between the pin and theyoke and allow such spaces to be removed during assembly.

As mentioned above, by providing machined parts having tight tolerancesand a counter-bored threaded hole for the shoulder screw ensures veryprecise alignment between the hinged assemblies. Such precise alignmentis significant in applications having mechanical and electricalinterconnects (e.g. including, but not limited to blind mateinterconnects) since precise alignment to ensure interconnects can besuccessfully made. No other alignment features are needed between theassemblies.

As also mentioned above, in preferred embodiments, the hinge is selfsupporting during rotation. This is accomplished by properly sizing thespring to firmly hold the assembly being rotated in the retractedposition during rotation. This prevents accidental contact and potentialdamage.

As also mentioned above, in preferred embodiments, the translationelement provides a true vertical translation. In other embodiments,off-axis vertical translations may be preferred or even necessary. Thismay be accomplished, for example, by utilizing an off-angle or curvedshoulder screw and appropriately modified hinge assembly and spring. Itshould be appreciated that the spring may be provided as a compressionspring, an extension spring or another type of spring. The translationlength can be modified by shortening or lengthening the shoulder screw.It should also be appreciated that any type of screw or pin may also beused.

As illustrated by reference numerals 76, 77 and 78 in FIG. 7,translating hinge 80 provides rotation in two orthogonal directions withrespect to the direction of translation. As shown in FIG. 7, referencenumeral 76 corresponds to a direction of translation for hinge 80.Reference numeral 77 corresponds to a first direction of rotation forhinge 80 while reference numeral 78 corresponds to a second orthogonaldirection of rotation for hinge 80.

It should be thus be appreciated that translating hinge 80 translates ina first direction (e.g. a direction which is perpendicular to matingsurfaces between two objects) and that rotation can occur in either oftwo directions. In particular, the translating hinge can be made torotate in a direction which is orthogonal to the direction oftranslation as indicated by reference numeral 77 in FIG. 7 (and asillustrated by reference numerals 67 in FIG. 5B and reference numeral 74in FIG. 5C) and/or the translating hinge can be made to rotate in adirection which is parallel to the mating surfaces (as indicated byreference numeral 78 in FIG. 7).

It should be appreciated, however, that it is important (and in someinstances required) for at least two or more of the axis (depending onthe number of hinges used) to be inline with each other. In other words,either all of the axis of rotations or all of the axis of translationshave to be aligned to prevent binding of the translating hinges witheach other during their translating/rotating operations.

Referring now to FIGS. 8-8F in which like elements are provided havinglike reference designations throughout the several views, translatinghinges 110 couple a first object 112 to a second object 116. 84.Translating hinges 110 operate in the same manner as translating hinges30, 52 and 80 described above in respective ones of FIGS. 1-7A. A secondpair of translating hinges 116 couple the second object 114 to a thirdobject 118. Translating hinges 116 operate in the same manner astranslating hinges 30, 52 and 80 described above in respective ones ofFIGS. 1-7A. It should be appreciated that at least one of thetranslating hinges 110 in FIGS. 8-8F do not include springs.

The translating hinges 110, 116 allow more than two layers of componentsto be hinged together and independently accessible. For example, a stackof three objects 112, 114, 188 or more than three objects can be coupledvia translating hinges. Furthermore since the translation height of thetranslating hinges 1112, 116 can be adjusted, the translating hinges cancouple objects of difference thicknesses (i.e. different heights). Forexample, in FIGS. 8-8F objects 112, 114 and 118 are all provided havingdifferent heights. Thus, the translating hinge itself is scalable tooperate with objects of different sizes and shapes while at the sametime providing system scalability (i.e. multiple translating hinges canbe able to stack three or more layers of objects as shown in FIGS.8-8F).

In view of the above, it is submitted that that scope of the patentshould not be limited to the described embodiments, but rather should belimited only by the spirit and scope of the following claims.

1. A radio frequency (RF) system comprising: a first heat sink assemblyof the RF system having a first surface; a second heat sink assembly ofthe RF system having a first surface and disposed over said first heatsink assembly, the first and second heat sink assemblies providingcooling to electronic components; a translating hinge coupled to saidfirst and second heat sink assemblies, said translating hinge configuredto translate in a direction normal to the first surface of a first oneof said first and second heat sink assemblies and to rotate the secondheat sink assembly away from the first heat sink assembly, wherein saidtranslating hinge comprises: a translation element configured to movebetween a closed position and a translated position with the movementbeing solely in a substantially vertical direction between the firstheat sink assembly and second heat sink assembly by raising the secondheat sink assembly with respect to the first heat sink assembly, thevertical direction being perpendicular to mating surfaces of the firstand second heat sink assemblies; and a rotating assembly coupled to saidtranslation element, said rotating assembly configured to allow thesecond heat sink assembly to be rotated relative to the first heat sinkassembly when the translation element is in a translated position. 2.The RF system of claim 1 wherein said translation element comprises: ahinge pin having first and second opposing surfaces with a first or topsurface of said hinge pin having a hole provided therethrough; a pair ofyoke blocks movably coupled to and projecting from opposing ends of saidhinge pin, said yoke blocks coupled to a first one of said first andsecond heat sink assemblies; a screw disposed through the hole in saidhinge pin and coupled to a second one of said first and second heat sinkassemblies; and a spring disposed over the shank of the screw.
 3. The RFsystem of claim 1 wherein said rotating assembly comprises: a pair ofyoke blocks rotatably coupled to said translation element and coupled toa first one of said first and second heat sink assemblies such that saidsecond heat sink assembly can rotate about said translation element. 4.The RF system of claim 1 wherein said translation element comprises: ahinge pin having a bore therethrough; a screw disposed through the borein said hinge pin; and a spring disposed over the screw with a first endof said spring disposed against a first surface of said hinge pin.